[Bug 44310] WritePrivateProfileString doesn't check for flush errors

https://bugs.winehq.org/show_bug.cgi?id=44310

--- Comment #13 from Fabian Maurer  ---
> It probably doesn't matter in this case, but note that there's nothing that
> says that a boolean must be TRUE, any non-zero value would do. So printing
> it is not necessarily useless.
>
> For the same reason, your &= trick is not a good idea.

Is that "&=" a real concern at this point? Because I think it makes it easier
to read while it's pretty easy to check that it's safe.